Yeah, we don't see much cold weather here, "freezing" for me is anything below 60 degrees
I think what affected my range those couple of cold days was the defroster, which in an EV is all electric. It siphoned a couple miles of range off before I had even moved the car.
I heard you can "precondition" the Volt for heat/defroster while it's being charged, but when I read about it in the manual it said it'll still use some kWh if you charge with the 120v cable like I do.
BTW, I found out yesterday why my car has been fogging up so bad. The culprit was the sunshade that I have been tucking into the doors. When it rains the straps on the sunshade wick some water into the car and in the morning this becomes fog.
I won't be using it any time they're predicting rain in the future